This invention relates to improved lifting capabilities of a solid wing that has a motor driven, flap mechanism that oscillates over a range of frequencies and over a range of angular deflections.
Over the past few years, there has been a great deal of interest in unsteady aerodynamics in several areas of air vehicle research from fighter aircraft to missile dynamics. Generally, the research falls into two basic categories: unsteady effects that produce destructive vibrational effects with detrimental stability and control, and those effects that may be used in a positive way. Aerodynamic research involving wings and airfoils continues to search for ways to improve the lifting characteristics of airfoils by whatever means for purposes of improved flight parameters, larger payload capability or better handling characteristics at predetermined velocities. Towards this end, U.S. Pat. No. 4,867,396 to Barnaby S. Wainfan, issued on Sep. 19, 1989, and assigned to the Lockheed Corporation discloses that it is known to fixedly attach a small flap-like device to the trailing edge of an airfoil to improve the coefficient of lift and reduce the coefficient of drag. The flap is a flat, single plate-like member having a length of between 0.5% to 1.50% of the chord of the airfoil and is fixedly positioned at a downward angle to the chord of between 5.degree. and 25.degree.. Preferably, the length of the flap is approximately 1% of the chord and the preferred angle to the chord is 20.degree.. It has been found that the above change in the aerodynamic characteristics provides an overall increase in fuel efficiency. However, this improvement still falls short of providing the dramatic improvement in lift characteristics that is obtained by the present invention.
Also in Arena, U.S. Pat. No. 5,098,043, a flap is rotatably connected to a wing and the flap is deflected in a purely static manner. The present invention is a dynamically oscillating flap that produces an increase in the lifting capabilities of the wing. This increase in the lift is particularly effective at set frequencies and at predetermined angular deflections.